<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
    
      div{
          width: 300px;
          height: 300px;
          background-color: lawngreen;
          margin: 200px auto;
          /* 2d转换 */
          transform: rotate(-30deg);
      }


    </style>
</head>
<body>
    
       <div></div>


</body>
</html>